Lamp basing oven



June 8, 1965 J. J. PLESCIA 3,188,064

LAMP BASING OVEN Filed July 12. 1961 W Inveervlror:

Joseph J. PLescia W I b pw/T C His Aft-iv 1 3,188,064 LAMP BASING OVEN Joseph J. Plescia, Euclid, Ghio, assignor to General Electric Company, a corporation of New York Filed duly 12, 1961, Ser. No. 123,561 2 (Ilairns. (Cl. 263-4) This invention relates tobasing ovens for baking the cement in bases attached to the ends of glass envelopes of electric lamps or similar devices.

Basing ovens heretofore employed have generally comprised a cup shaped member in which the base is received and which is heated by burners from opposite sides in a manner to more or less uniformly heat the cup around its periphery and thereby heat the enclosed base by radiation and conduction to thereby, in turn, heat the thermoplastic cement within the base to cure and set it. However, there are applications where it is not feasible to direct fires from opposite sides of the cup or oven, as where such cups are located extremely close together on a turret or other carrier. In such cases, directing the fires upon only one side of the cup results in overheating of that side and insufficient heating of the opposite side of the cup.

Accordingly, it is an object of the invention to provide a novel oven structure which will afford substantially uniform heating around the periphery of the base when heating fires are directed thereto from one side only.

The invention is described in detail hereinafter in connection with the accompanying drawing wherein:

FIG. 1 is a perspective view of a lamp holder and oven arrangement at one end of a double ended fluorescent lamp;

FIG. 2 is aside elevation corresponding to FIG. 1 with the basing oven shown in section; and

FIG. 3 is a plan view of the basing oven and heating burners.

Referring to the drawing, there is shown a fluorescent lamp comprising a tubular glass envelope 1 carrying at each end thereof a base comprising a cylindrical cup shaped metal shell 2 having a pair of terminal contact pins 3 insulatively attached to and projecting from the bottom or end of the base shell. At the inside of the shell 2 is a ring or annulus of basing cement 4 of Well-known thermosetting composition which is to be heated and cured to unite the base firmly to the envelope 1.

The lamp envelope is supported by a holder comprising a pair of L-shaped jaws 5 which are pivoted on pins 6 carried by a bracket 7 aflixed to a turret 8. As herein illustrated, the turret 8 is horizontal and lamps are held vertically. It will be understood that in a so-called horizontal finishing machine the turret 8 may be one of a pair of turrets in spaced vertical planes and rotatable about a horizontal axis. In either the horizontal or vertical type of finishing machine the lamps may be supported at both ends by similar holders on spaced turrets.

Each of the jaws 5 carries a pair of bulb-engaging pad members in the form of adjustable screws 9 having ball tipped ends arranged in a circle. The jaws 5 are normally biased to closed position 'by a'spring 10 extending therebetween, and are constrained to move in unison by the interlocking arrangement of arms 11 and 12 (FIG. 1) carrying a pin 13 on one arm 11 engaging a slot 14 in the other arm 12. The jaws 5 are movable to open position by upward movement of a cam wedge 15 into engagement with the inner opposing faces of another pair of arms 16 on the jaws 5. The said wedge 15 is carried by the end of an adjustable tongue member 17 which is fixed in a slot in a U-shaped bracket 18 which is arranged to slide on a rod 19 which is fixed to the turret 8. The said bracket 18 is normally biased downward toward the jaws 5 by a spring 20 which is attached at one end to the bracket 13 and at its other end to a post 21 attached to the turret 8.

United States Patent 0 "ice kid

The bracket 18 also carries a basing oven indicated generally at 22. The oven comprises a holder plate portion 23 which is attached to bracket 13 by screws 24, and an inverted cylindrical cup portion 25 upstanding from the upper surface of the plate portion 23. The lamp base 2 is snug-1y received in the cup portion 25 against its bottom end which has a central aperture 26 therein through which project the lamp base terminals 3. The lower portion of the cup 25 is conically flared outward at 27 and terminates in an annular flange 28 which is held against the margin of an opening 29 in plate 23 by screws 30.

The upper surface of plate 23 also carries a bafile member comprising generally U-shaped side walls 31 spaced from the cup portion 25 and extending along opposite sides of and completely around the back of the said cup portion. The baflie also includes a cover or roof portion 32 at the back and sides of the cup portion 25 and which extends between the side walls 31 and the said cup portion 25 and is provided with a vent opening. Preferably, the vent opening is provided by terminating the cover portion 32 a short distance from the cup portion 25, thereby providing a narrow arcuate vent opening 33 around the back of the cup portion.

As shown in FIG. 3, the baking heat is supplied by burner means, preferably a pair of burners 34 which are arranged to be located at the front of the oven to direct hot gas jets thereinto. The burners 34 are preferably arranged to direct relatively wide, flat flames which terminate short of the oven but which direct hot gas jets over the upper surface of plate 23 and against the front of the cup portion 25 at either side of the center thereof, and into the passages between respective side walls 31 and the sides of the cup portion 25. The hot gas jets are channeled by the side walls 31 of the baflle around the back of the cup portion 25 and escape through the vent opening 33.

By virtue of the baffle structure 31-32, the back end of the cup portion 25 is heated quite uniformly along with the front thereof, thereby also uniformly heating the lamp base 2 within the cup portion to effectively heat and cure the cement 4. The plate portion 23 and conical cup portion 27 serve to shield the end of the glass envelope 1 from overheating.

It will be understood that at the time a lamp envelope 1 carrying bases 2 is loaded into the pairs of jaws 5 (one for each end of the lamp), the bracket 18 and oven 22 are in a retracted position (raised, in FIGS. 1 and 2) with the cam wedge 15 located between the jaw arms 16 and holding the jaws 5 open. The bracket 18 is then moved downward in FIG. 1 and FIG. 2 to permit closing of the jaws 5 by the spring 10 and to bring the cup portion 25 of the oven 22 into engagement with the base 2 to clamp it firmly against the end of the envelope 1. During the course of indexing of the turret 8, the lamp 1 is brought to a position in alignment with the burners 34 (FIG. 3), and preferably in alignment with several successive pairs of burners like 34. The effect of the baflle structure around the cup 25 is such that the basing cement 4 in the lamp base 2 is baked on a short time-temperature cycle which is well adapted to high speed operation of the turret 8 and which provides adequate and uniform heating of the lamp base while avoiding overheating.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A basing oven for baking the cement in a cylindrical base attached to the end of a glass envelope comprising a holder plate, an inverted cylindrical cup portion upstanding from a surface of said holder plate and being of a diameter to snugly receive said base over its full circumference, a baffle member on the said surface of said holder plate comprising generally U-shaped side walls spaced from said cup portion and extending along opposite sides and completely around the back of said cup portion while leaving the front of said cup portion exposed and including a cover portion at the back and sides of said cup portion, said cover portion extending between the upper edges of said side walls and said cup portion and being provided with a restricted vent opening, and burner means arranged at the front of said oven to direct respective hot gas jets against the exposed front of said cup portion at either side of the center thereof and into the passages between said cup portion and the legs of said U-shaped walls of the baffle member.

2. A basing oven for baking the cement in a cylindrical base attached to the end of a glass envelope comprising a holder plate, an inverted cylindrical cup portion upstanding from a surface of said holder plate and being of a diameter to snugly receive said base over its full circumference, a baflle member on the said surface of said holder plate comprising generally U-shaped side walls spaced from said cup portion and extending along opposite sides and completely around the back of said cup portion while leaving the front of said cup portion exposed and including a cover portion at the back and sides of said cup portion and extending from the upper edge of said side walls to within a short distance of the upper edge of said cup portion to provide thereat a narrow arcuate vent opening, and burner means arranged at: the front of said oven to direct respective hot gas jets against the exposed front of said cup portion at either side of the center thereof and into the passages between said cup portion and the legs of said U-shaped walls of the baffie member. 7

References Cited by the Examiner UNITED STATES PATENTS 3,013,927 12/61 McDougal 156-424 EARL M. BERGERT, Primary Examiner. 

1. A BAISING OVEN FOR BAKING THE CEMENT IN A CYLINDRICAL BASE ATTACHED TO THE END OF A GLASS ENVELOPE COMPRISING A HOLDER PLATE, AN INVERTED CYLINDRICAL CUP PORTION UPSTANDING FROM A SURFACE OF SAID HOLDER PLATE AND BEING OF A DIAMETER TO SNUGLY RECEIVE SAID BASE OVER ITS FULL CIRCUMFERENCE, A BAFFLE MEMBER ON THE SAID SURFACE OF SAID HOLDER PLATE COMPRISING GENERALLY U-SHAPED SIDE WALLS SPACED FROM SAID CUP PORTION AND EXTENDING ALONG OPPOSITE SIDES AND COMPLETELY AROUND THE BACK OF SAID CUP PORTION WHILE LEAVING THE FRONT OF SAID CUP PORTION EXPOSED AND INCLUDING A COVER PORTION AT THE BACK AND SIDES OF SAID CUP PORTION, SAID COVER PORTION EXTENDING BETWEEN THE UPPER EDGES OF SAID SIDE WALLS AND SAID CUP PORTION AND BEING PROVIDED WITH A RESTRICTED VENT OPENING, AND BURNER MEANS ARRANGED AT THE FRONT OF SAID OVEN TO DIRECT RESPECTIVE HOT GAS JETS AGAINST THE EXPOSED FRONT OF SAID CUP PORTION AT EITHER SIDE OF THE CENTER THEREOF AND INTO THE PASSAGES BETWEEN SAID CUP PORTION AND THE LEGS OF SAID U-SHAPED WALLS OF THE BAFFLE MEMBER. 